Ring canal blower

ABSTRACT

The ring canal blower has a housing with a lateral canal in front of one or both front sides of a rotor for compressing gases as well as intake and pressure connection stubs which are connected directly to each other via the canal or canals. In order to prevent a heat build-up, the housing has an outlet for hot gas located between the intake and pressure connection stubs as viewed in the direction of rotation of the rotor as well as an inlet for cool gas. The inlet for the cool gas communicates with the hot gas outlet via the rotor compartments that pass by. The outlet and inlet serve to draw off the hot gas disposed within the rotor blade compartments while replenishing these compartments with cool gas.

United States Patent [191 Engels Jan. 29, 1974 RING CANAL BLOWER [73] Assignee: Siemens Aktiengesellschaft,

Munchen, Germany [22] Filed: June 12, 1972 [21] Appl. No.: 261,613

[30] Foreign Application Priority Data June 26, 1971 Germany 2131952 [52] US. Cl. 415/53 T, 415/213 T, 415/178 [51] Int. Cl. F04d 17/00, F04d 17/10 [58] Field of Search 415/53 T, 213 T, 144

[56] References Cited UNITED STATES PATENTS 3,095,820 7/1963 Sanborn et al. 415/213 T 1,529,815 3/1925 Siemen et al 415/53 T FOREIGN PATENTS OR APPLICATIONS 101,871 l2/l'925 Austria 415/53 T 11/1941 France 415/213 T l2/l934 Italy 415/213 T Primary Examiner-Henry F. Raduazo Attorney, Ag n or F irm- Kenyon & Kenyon, Reilly, Carr & Chapin [5 7] ABSTRACT The ring canal blower has a housing with a lateral canal in front of one or both front sides of a rotor for compressing gases as well as intake and pressure connection stubs which are connected directly to each other via the canal or canals. In order to prevent a heat build-up, the housing has an outlet for hot gas located between the intake and pressure connection stubs as viewed in the direction of rotation of the rotor as well as an inlet for cool gas. The inlet for the cool gas communicates with the hot gas outlet via the rotor compartments that pass by. The outlet and inlet serve to draw off the hot gas disposed within the rotor blade compartments while replenishing these compartments with cool gas.

5 Claims, Drawing Figures PATENIEBJANZSM'M 3 788 766 SHEET 1 OF 2 PRIOR ART Fig. 8

RING CANAL BLOWER FIELD OF THE INVENTION This invention relates to a ring-canal blower for the compression of a gas.

BACKGROUND OF THE INVENTION of the housing through the intake connection stub due to the suction force created by a rotating rotor within the housing The gas is then subjected to an increasing pressure while being conveyed to the pressure connection stub due to the revolution of the gas in rotor compartments between the blades of the rotating rotor and the gas situated in a lateralcanal. The gas in the lateral canal is then expelled in a compressed state through the pressure connection stub.

However, as the gas is increasingly compressed, the temperature of the gas increases. Further, only the gas that is conveyed in the lateral canal escapes through the pressure connection stub. The heated gas within the rotor compartments remains and is directed from the pressure side of the housing to the intake side. Upon reaching the intake side, this heated pressurized gas expands and warms up the fresh supply of gas drawn-in through the intake connection stub. Thus, compression of the fresh gas starts at the beginning of the lateral canal at an elevated temperature. This initiation of compression of gas at an elevated temperature is detrimental, particularly at higher pressure ratioes since the drawn-in gas quantity becomes relatively small in the ring-canal blower, and even drops to zero, at the highv est pressures. With increasing periods of operation, a steady increase in temperature thus takes place not only at the intake point but also in the entire blower as the external cooling of the gas remains ineffective, particularly if there is no gas throughput at zero output. Further, the increased temperature of the blower, in spite of any cooling of the housing, causes a reduction in the efficiency of the blower.

Accordingly, it is an object of the invention to prevent the heating-up of a gas drawn into a ring-canal blower by gas within the blower which is conveyed from the pressure side towards the intake side in the rotor compartments.

It is another object of the invention to maintain the housing of a ring-canal blower in a cool condition.

It is another object of the invention to increase the efficiency of a ring-canal blower.

It is another object of the invention to reduce the heating-up effect of a compressed gas in a ring-canal blower in a simple manner.

SUMMARY OF THE INVENTION Briefly, the invention provides a ring-canal blower which has a housing, an intake connection stub and a pressure connection stub in one face and a lateral canal connecting the intake connection stub to the pressure connection stub with an outlet in the housing between the pressure connection stub and intake connection stub for expelling hot gas as well as an inlet for cool gas. The outlet is positioned so that the heated gas which is conveyed in the compartments of the rotor is expelled through the outlet while the inlet is positioned so that cool gas can be drawn into the rotor compart ments as the rotor passes by the intake. As a result, large temperature increases in the blower which would otherwise be caused by the transport of hot gas to the intake side of the blower is prevented.

In one embodiment, the outlet for the heated gas is located at the periphery of the blower housing while the inlet for the cool gas is located in the same radial plane as the outlet so as to communicate with the outlet via the rotor compartments. In this embodiment, the heated gas can be expelled to the surrounding atmosphere while the cool gas is drawn-in from a cooler part of the surrounding atmosphere.

In another embodiment, the outlet and inlet are connected to a closed recirculating system in which the expelled hot gas is cooled by a suitable means prior to reentry into the blower.

DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a top view of an open housing of a ring-canal blower according to the prior art with the rotor removed.

FIG. 2 illustrates a view taken on line 22 of FIGS. 1 and 6.

FIG. 3 illustrates a view taken on line 3-3 of FIGS.

1 and 6.

FIG. 4 illustrates a view taken on line 44 of FIGS.

1 and 6.

FIG. 5 illustrates a view taken on line 5-5 of FIGS.

1 and 6.

FIG. 6 illustrates a top view of an open housing of a ring-canal blower according to the invention.

FIG. 7 illustrates a view taken on line 7-7 of FIG. 6 showing a hot gas outlet and a cool gas inlet according to the invention.

FIG. 8 illustrates a schematic view of a closed system utilizing a ring-canal blower according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 6, a single state ring-canal blower has a housing G of two-part construction which mounts a rotor (not shown) of known construction therein. The housing G includes a central aperture W for passage of the shaft (not shown) of the rotor. Each part of the housing G is provided with an intake connection stub S and a pressure connection stub D on the front face. As shown respectively in FIGS. 3 and 4, the intake connection stubs S and the pressure connection stubs D are disposed on opposite sides of the housing G from each other. In addition, a lateral canal K is formed in each housing half and extends from the intake connection stub S to the pressure connection stub D therein so as to freely communicate the intake connection stub S with the pressure connection stub D. As shown in FIG. 6, each lateral canal K extends in the direction of rotation of the rotor (not shown) as indicated by the arrow.

Referring to FIGS. 3 and 4, compartments Z are located between the blades of the rotor L in facing relation to the intake and pressure connection stubs S, D. Also, as shown in FIG. 2, the compartments Z are located in facing relation to the lateral canals K.

Referring to FIGS. 6 and 7, the blower housing G is also provided with an outlet A which is located in the periphery of the housing at a suitable inclined angle and between the pressure onnection stub D and the intake connection stub S as viewed in the direction of rotor rotation. Also, an inlet E is provided in each half part of the housing G between the pressure connection stubs D and the intake connection stubs S and in the zone of the lateral canals K. The outlet A and inlets E are positioned relative to each other so as to be in communication with each other when a rotor compartment Z passes by.

During operation, gas is drawn in through the intake connection stubs S (FIG. 4) and passed into the respective lateral canals K. Next, the gas is conveyed through the canals K and within the compartments Z (FIG. 2) and compressed. Upon reaching the pressure connection stubs D, the compressed gas in the canals K is expelled (FIG. 5). Also, after passage by the pressure connection stubs D, the compartments Z become aligned with the inlets E and the outlets A (FIG. 7). At this time, the hot gas within the aligned rotor compartments Z is expelled under centrifugal force through the inclined outlet A while cool gas from a suitable source is drawn into and fills the compartments Z through the inlets E. Thereafter, the rotor compartments Z move into alignment with the intake connection stubs S and fresh gas is drawn into the lateral canals K. In this manner, no heat transport takes place via the rotor compartments Z from the pressure connection stubs D to the intake connection stubsS. Thus, heating up of the blower can be kept low even at zero output and even if the housing is not cooled at all. A high efficiency is thus achieved.

Referring to FIG. 8, in order to avoid mixing air with a pumped gas, or in the case of series-connected stages in multi-stage blowers, the expelling of the hot compressed gas through the outlet an the inlet of cool gas can take place in a closed circuit KR. To this end, the blower is constructed in a similar manner to that described in FIGS. 6 and 7 above; however, an outlet A for the hot gas is connected directly to the closed cooling circuit KR at one end while an inlet E for a cool gas is connected directly to the closed cooling circuit KR at an opposite end. The closed circuit KR includes a cooler KU which is exposed to the outside environment in a suitable manner so as to effect a cooling of the hot gas flowing therethrough in a heat exchange manner. In addition, in order to overcome the'resistance of the closed circuit KR, a circulation pump U is provided downstream of the cooler KU to assist the basic output of the hot gas via the outlet A which occurs due to centrifugal force.

In operation, hot gas from the rotor compartments, as explained above, exits via the outlet A and is passed into the closed circuit KR. Thereafter, the hot gas flows through the cooler KU and is cooled to a suitable temperature. The cooled gas thenpasses to the pump U and is pumped back into the blower housing G via the inlet E.

What is claimed is:

1. A ring-canal blower for the compression of gas comprising a housing having at least one from face;

a rotor having rotor compartments open at the sides and periphery of said rotor within said housing; an intake connection stub in said face of said housing communicating with said ring canal;

a pressure connection stub in said face of said hous ing communicating with said ring canal;

a lateral canal in said housing forming a portion of said ring canal and freely connecting said intake connection stub to said pressure connection stub;

an outlet inclined in the direction of rotation of said rotor, communicating with the periphery of said ring canal in said housing between said pressure connection stub and said intake connection stub for expelling hot gas under centrifugal forces; and

an inlet in said housing positioned radially inwardly of said outlet between said pressure connection stub and said intake connection stub for drawing in cool gas, said inlet and said outlet being in communication with each other via each respective rotor compartment during rotation of said rotor.

2. A ring-canal blower as set forth in claim 1 wherein said outlet is disposed in the periphery of said housing and said inlet is disposed in said face of said housing radially inwardly of said outlet.

3. A ring-canal blower as set forth in claim 1 further comprising a closed cooling circuit connecting said outlet to said inlet for cooling of the hot gas expelled from said outlet and returning the cooled gas to said inlet.

4. A ring-canal blower as set forth in claim 3 wherein said closed cooling circuit includes a cooler therein for cooling the hot gas expelled from said outlet.

5. A ring-canal blower as set forth in claim 3 wherein said closed cooling circuit incldes a circulation pump for pumping the cooled gas through said inlet into said housing. 

1. A ring-canal blower for the compression of gas comprising a housing having at least one front face; a rotor having rotor compartments open at the sides and periphery of said rotor within said housing; an intake connection stub in said face of said housing communicating with said ring canal; a pressure connection stub in said face of said housing communicating with said ring canal; a lateral canal in said housing forming a portion of said ring canal and freely connecting said intake connection stub to said pressure connection stub; an outlet inclined in the direction of rotation of said rotor, communicating with the periphery of said ring canal in said housing between said pressure connection stub and said intake connection stub for expelling hot gas under centrifugal forces; and an inlet in said housing positioned radially inwardly of said outlet between said pressure connection stub and said intake connection stub for drawing in cool gas, said inlet and said outlet being in communication with each other via each reSpective rotor compartment during rotation of said rotor.
 2. A ring-canal blower as set forth in claim 1 wherein said outlet is disposed in the periphery of said housing and said inlet is disposed in said face of said housing radially inwardly of said outlet.
 3. A ring-canal blower as set forth in claim 1 further comprising a closed cooling circuit connecting said outlet to said inlet for cooling of the hot gas expelled from said outlet and returning the cooled gas to said inlet.
 4. A ring-canal blower as set forth in claim 3 wherein said closed cooling circuit includes a cooler therein for cooling the hot gas expelled from said outlet.
 5. A ring-canal blower as set forth in claim 3 wherein said closed cooling circuit incldes a circulation pump for pumping the cooled gas through said inlet into said housing. 